Solve for $x$ and $y$ using substitution. ${2x-3y = -9}$ ${x = 2y-7}$
Since $x$ has already been solved for, substitute $2y-7$ for $x$ in the first equation. ${2}{(2y-7)}{- 3y = -9}$ Simplify and solve for $y$ $4y-14 - 3y = -9$ $y-14 = -9$ $y-14{+14} = -9{+14}$ ${y = 5}$ Now that you know ${y = 5}$ , plug it back into $\thinspace {x = 2y-7}\thinspace$ to find $x$ ${x = 2}{(5)}{ - 7}$ $x = 10 - 7$ ${x = 3}$ You can also plug ${y = 5}$ into $\thinspace {2x-3y = -9}\thinspace$ and get the same answer for $x$ : ${2x - 3}{(5)}{= -9}$ ${x = 3}$